An atomic layer etching method capable of precisely etching a metal thin film at units of atomic layer from a substrate including the metal thin film, includes forming a metal layer on a substrate, and etching at least a portion of the metal layer. The etching at least a portion of the metal layer includes at least one etching cycle. The at least one etching cycle includes supplying an active gas onto the metal layer, and supplying an etching support gas after supplying the active gas. The etching support gas is expressed by the following general formula wherein each of R1, R2, R3, R4 and R5 independently includes hydrogen or a C1-C4 alkyl group, and N is nitrogen.
Legal claims defining the scope of protection, as filed with the USPTO.
2. The atomic layer etching method of claim 1, wherein the metal layer includes at least one of iridium (Ir), ruthenium (Ru), rhodium (Rh), molybdenum (Mo), copper (Cu), antimony (Sb), aluminum (Al), titanium (Ti), nickel (Ni), tantalum (Ta), zirconium (Zr), hafnium (Hf), tungsten (W), or cobalt (Co).
3. The atomic layer etching method of claim 1, wherein a temperature of the substrate is in a range from 150° C. to 200° C.
4. The atomic layer etching method of claim 1, wherein the active gas includes at least one of fluorine (F2), chlorine (Cl2), bromine (Br2), iodine (I2) C1-7 alkyl halide, or tri C1-7 alkyl silyl halide.
5. The atomic layer etching method of claim 1, further comprising performing a pre-treatment process that reduces a surface of the metal layer, before the supplying the active gas, wherein the performing the pre-treatment process includes supplying a reducing gas.
6. The atomic layer etching method of claim 5, wherein the reducing gas includes at least one of hydrogen (H2), ammonia (NH3), silane (SiH4), borane (BH3), diborane (B2H6), phosphine (PH3), or hydrazine (N2H4).
7. The atomic layer etching method of claim 5, further comprising removing residual reducing gas after the performing the pre-treatment process.
12. The atomic layer etching method of claim 11, wherein the metal layer includes at least one of iridium (Ir), ruthenium (Ru), rhodium (Rh), molybdenum (Mo), copper (Cu), antimony (Sb), aluminum (Al), titanium (Ti), nickel (Ni), tantalum (Ta), zirconium (Zr), hafnium (Hf), tungsten (W), or cobalt (Co).
13. The atomic layer etching method of claim 11, wherein the active gas includes at least one of fluorine (F2), chlorine (Cl2), bromine (Br2), iodine (I2), C1-7 alkyl halide, or tri C1-7 alkyl silyl halide.
16. The atomic layer etching method of claim 14, wherein the reducing gas includes at least one of hydrogen (H2), ammonia (NH3), silane (SiH4), borane (BH3), diborane (B2H6), phosphine (PH3), or hydrazine (N2H4).
18. The semiconductor device manufacturing method of claim 17, wherein the supplying the etching support gas includes supplying the etching support gas at a feeding dosage of 50 Torr·sec to 70 Torr·sec.
19. The semiconductor device manufacturing method of claim 17, wherein the active gas and the etching support gas do not react with the interlayer insulating film.
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November 26, 2021
February 13, 2024
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